Magnetic valve incorporating a flat armature

ABSTRACT

A MAGNETIC VALVE ASSEMBLY HAVING A SPECIALLY FORMED ONE PIECE FRAME WHICH FORMS A VALVE CHAMBER AND A HOLLOW COIL SUPPORT. THE COIL SUPPORT HAS A COIL WOUND THEREON AND ALSO PROVIDES SUPPORTING STRUCTURE FOR AN E-SHAPED MAGNET. THE FRAME HAS CHANNELS OR GROOVES FOR RECEIVING THE TWO ENDS OF THE COIL AND POCKETS FOR RECEIVING THE TWO ENDS OF THE COIL AND POCKETS FOR RECEIVING CONNECTING LUGS. THE FRAME WITH THE ASSOCIATED COIL AND MAGNET IS SURROUNDED WITH A FORM FITTING PLASTIC ENVELOPE WHICH IS APPLIED WITH A MOLDING OPERATION.

Feb. 9, 1971 6 BORSCHERS 3,562,686

MAGNETIC VALVE INCORPORATING A FLAT ARMATURE Filed June 20, 1969 United States Patent 3,562,686 MAGNETIC VALVE INCORPORATING A FLAT ARMATURE Alwin Borschers, Flensborg, Germany, assignor to Danfoss A/ S, Nordborg, Denmark, 2 company of Denmark Filed June 20, 1969, Ser. No. 835,184 Int. Cl. H01f 3/00, 7/08 US. Cl. 335-279 8 Claims ABSTRACT OF THE DISCLOSURE The invention relates to a magnetic valve having an attachment which contains a coil and magnet laminations, and the frame on the end-face of which, together with a valve housing, defines a valve chamber in which is located a fiat armature controlling the valve, the attachment being sealed relative to the valve chamber by a thin dividing layer disposed in the magnetic path.

The flat armature can control the colsure member of the magnetic valve either directly or indirectly, for example, by actuating an auxiliary valve in the case of a diaphragm valve controlled by an auxiliary force.

In a known magnetic valve of this kind, a coil and a coil carrier, the axis of which is at right-angles to the direction of actuation, are provided. The magnet laminations passing through the coil, have two limbs which extend parallel with the flanges of the coil support and are provided at their free ends with feet that face each other. The entire arrangement is united by a composition filled into the attachment, the frame also being formed of this composition. The free end-faces of the feet of the magnet laminations and the entire face of the attachment, presented to the valve chamber, are covered with a thin metal foil, which serves as the sealing separating layer and is required for supporting a rnulti-part fixing arrangement in the valve chamber. This arrangement is very expensive and complicated as regards its number of parts and its assembly.

The object of the invention is to provide a magnetic valve of the initially described kind, which is of considerably simpler construction and can be more readily assembled.

According to the invention, this object is achieved by forming in one piece the frame, a hollow coil support, the axis of which is parallel with the direction of the armature-travel, and the dividing layer, which seals the space within the coil support at one end, by inserting E-shaped or U-shaped magnet laminations by one of their limbs into said space from the open end, and by surrounding the coil support, coil and magnet laminations with a subsequently fitted envelope of plastic material and connecting the latter to the frame. In this arrangement, the joining of the frame to the coil support and the dividing layer saves a considerable number of individual components. The coil can be conveniently wound on to the coil support. The magnet laminations can be pushed into or over the coil support without difficulty and, if required, even automatically. The laminations are then held in position by the subsequently fitted envelope of plastics material which, at the same time, seals off the magnet system against the atmosphere.

Advantageously, ribs, over the envelope extends, are provided on the periphery of the frame. In this way the envelope can be firmly anchored to the frame.

Furthermore, pockets for accommodating the outer limbs of the E-shaped magnet laminations can be provided in the coil-support flange associated with the frame. In this way, the limbs of the magnet laminations can also be brought very close to the valve chamber in the vicinity of the pockets.

The magnet laminations can be of such dimensions that they make friction contact with the coil support at at least one point. On the one hand, this results in their being fixed in position to some extent upon assembly, while on the other hand the outer envelope of plastics material needs to provide only part of the force for retaining the laminations.

In a preferred embodiment, the magnet laminations are biased towards the bottoms of the pockets by the envelope. Such bias is obtained by, for example, using a plastics material which contracts upon curing. As a result of this bias, the laminations are pressed firmly against the bottoms of the pockets, so that there i no danger of an air-gap being present at this point.

Furthermore, the magnet laminations can contain incisions on the outside into which the envelope extends. This results in an additional meshing arrangement which retains the laminations.

In a further aspect of the invention, an annular recess for accommodating a return spring is provided in the flange associated with the frame and on that side presented to the valve chamber. Since the dividing layer is not inserted as a separate foil, the thick material of the coil-support flange can be used for the formation of this recess.

The coil-support flange remote from the frame can also be additionally shaped. Here, inlet and outlet grooves for the ends of the coil and two holders in which the connecting lugs can be clamped, are formed.

The invention will now be described in more detail by reference to an embodiment illustrated in the drawing, in which:

FIG. 1 is a front view, partly in section, of a magnetic valve in accordance with the invention,

FIG. 2 is a vertical section in the plane of FIG. 1 and through the attachment, without the outer envelope fitted,

FIG. 3 is a secion on line AA of FIG. 2, and

FIG. 4 is a plan view of the details shown in FIG. 2.

The magnetic valve illustrated has a valve housing 1, with a supply port 2 and a discharge port 3, and a valveseat 4, covered by a diaphragm 5. The diaphragm is clamped at its outer edge between the valve housing and an attachment 6 and has at its centre an insert 7 having a central bore 8, which can be covered at the top by the closure piece 9 of an auxiliary valve; the insert 7 also has a support plate 10. The diaphragm contains an opening 11. The closure member 9 is held by a plate 12 to which is connected a flat armature 13. The plate 12 is pressed into the closed position by a spring 14.

When the closure piece 9 closes the bore 8, the supply pressure builds up in the chamber above the diaphragm through the opening 11, and the main valve is closed. When, on the other hand, the closure member 9 is lifted, the pressure above the diaphragm can be relieved, and the main valve opens under the action of the return pressure applied only from below.

The attachment 6 consists of a base element 15, a coil 16, magnet laminations 17 and an envelope 18 of plastics material.

As can be seen more clearly from FIGS. 2 to 4, the base element is integral with a coil-support 19, having a bore 20, a thin dividing layer 21, sealing the bore at the bottom, and a frame 22, which consists of the lower coil-support flange 23 and a peripheral wall 24. The outer circumference of the frame carries ribs 25 on which is anchored the outer envelope 18' of plastics material. Contained in the underside of the flange 22 is an annular recess 26 in which is fitted the spring =14. On the top of the flange there are provided pockets 27 for accommodating the outer limbs of the E-shaped magnet laminations 17. Formed on the upper flange 28 of the coil-support 19 is a lug 29, which contains outlet grooves 30 for the ends of the coil 16, and holders 31 into which can be inserted connecting lugs 32 having clamping tabs 33.

A base element of this kind can be readily produced, e.g. by injection-moulding, in plastics material, for example a copolymer of polymethylene oxide. The coil 16 is wound on the base member so produced. The E- shaped laminations 17 are then introduced from above in such a way that the central web extends into the bore 20 and the two outer webs into the pockets 27. The magnet laminations are of such dimensions, relative to the base element, that a certain degree of clamping occurs at the points 34 and 35, this resulting in the laminations being firmly held by frictional force. Finally, the connecting lugs 32 are inserted and the ends of the wires soldered on at the point 36. The envelope 18 of plastics material is then applied in a mould and becomes anchored on the ribs 25 on the frame 22; it engages the magnet laminations 17 by way of recesses 37 at the lower end and also engages them at the upper end. Even if this envelope of plastics material contracts to only a slight degree, the magnet laminations 17 are biassed towards the bottom of the bore 20 and of the pockets 27.

An attachment so produced can be easily fitted on the valve housing 1, the diaphragm '5 being thereby firmly clamped. The flat armature 13 plus plate 12 and closure member 9 is relatively light and can be pulled upwards even when the magnetic force is small, since the magnetic circuit can be substantially closed except for the thin dividing layer.

What is claimed is:

1. A magnetic valve assembly comprising a frame having a partition portion, first wall means extending in one direction from said partition portion to form a valve chamber, an armature in said chamber, second wall means extending in the opposite direction from said partition to form a hollow coil support having an axis parallel to the travel direction of said armature, a coil surrounding said coil support, an E-shaped magnet having one leg thereof disposed in said coil support, and a plastic envelope in. closely surrounding form fitting engagement with said partition portion, said first and second wall means, said coil and said magnet.

2. A magnetic valve assembly according to claim 1 wherein said partition portion has circumferentially extending and axially spaced ribs, said plastic envelope having form fitting engagement with said ribs.

3. A magneticvalve assembly according to claim 1 including third wall means extending in said one direction from said partiti'tfn portion to form pockets for the outer legs of said magnet.

4. A magnetic valve assembly according to claim 1 wherein said trnagnet has a snug frictional contact with said coil support at least at one common point therebetween.

5. A magnetic valve assembly according to claim 3 .wherein said envelope biases said magnet towards the bottoms of said pockets.

6. A magnetic valve assembly according to claim 1 wherein said magnet has recesses formed therein, said envelope being in form fitting engagement with said recesses.

7. A magnetic valve assembly according to claim 1 wherein said partition has an annular recess, and a coil spring seated in said annular recess and having abutting engagement with said armature.

8. A magnetic valve assembly according to claim 1 wherein said coil support has a flange at the opposite end thereof from said partition, said coil support having two outlet channels for the two ends of said coil, and said coil support having two pockets for receiving connecting lugs.

References Cited UNITED STATES PATENTS 2,370,752 3/1945 Ray 335--245 2,909,713 10/1959 Hambor et a1 335-255 3,327,264 6/1967 Rodaway 3'3525 1X BERNARD A. GILHEANY, Primary Examiner US. Cl. X.R. 335261, 281 

